Association Between UrinaryMarkers of Nucleic Acid Oxidation andMortality in Type 2 Diabetes A population-based cohort study

OBJECTIVEdWe recently showed that RNA oxidation, estimated by urinary excretion of 8-oxo-7,8-dihydroguanosine (8-oxoGuo), independently predicted mortality in a cohort of 1,381 treatment-naive patients with newly diagnosed type 2 diabetes. In the present investiga-tion, we analyzed urine collected 6 years after the diagnosis to assess the association between urinary markers of nucleic acid oxidation and mortality in patients with established and treated diabetes. RESEARCH DESIGN AND METHODSdWe used data from the 970 patients who attended the screening for diabetes complications 6 years after the diagnosis. Cox proportional hazards regression was used to examine the relationship between urinary markers of DNA oxidation (8-oxo-7,8-dihydro-29-deoxyguanosine [8-oxodG] [n = 938]) and RNA oxidation (8-oxoGuo [n = 936]) and mortality. RESULTSdDuring a median of 9.8 years of follow-up, 654 patients died. Urinary 8-oxoGuo assessed 6 years after the diagnosis was significantly associated with mortality. The multivariate-adjustedhazard ratios for all-cause and diabetes-relatedmortality of patientswith 8-oxoGuo levels in the highest quartile compared with those in the lowest quartile were 1.86 (95 % CI 1.34–2.58) an